With the development of network technology, online meetings can be realized through the application of video software and one party can play video for another party, which brings great convenience to the users. Conventionally, when a user A and a user B want to start a video chat, user A can send a video invitation to user B, who can accept the video chat after receiving the video invitation. Meanwhile, a server can send commands to establish a video connection between client terminals of user A and user B. The client terminals of user A and user B first attempt to establish a direct channel connection. If the direct channel connection fails, the client terminals can a relay channel connection. When the audio and video connection is successful, audio and video transmission parameters can be adjusted at the client terminals. However, the adjustment of audio and video transmission parameters at the client terminals generally needs to revise a control logic of audio and video streaming at the client terminals. Thus, there is a need to release a new version of the application, which will increase operating costs, and the control of audio and video transmission parameters has poor flexibility.